An ETO war code £20 in Poor grade sold for €1,050 plus fees in a recent (November 2014) auction in Dublin. With several bidders, this was well above the estimate, and establishes the lower end of valuations for the war code £20.

Lot 261, Bank of Ireland £10, 1914 brought £1,800 plus fees.
Lot 312, National Bank £1 brought £1,700 plus fees.
A healthy price for both of these notes, pointing to a strengthening in the value of Old Notes here.
Lot 262 was interesting, a previously unrecorded variety of the small-sized Bank of Ireland £1 note.

Ploughman £10 notes continue to turn up in nice grade. The latest one, a Provincial Bank Forde signature (01PT 030439) 2.10.31 is out of a known run of gEF/AU grade notes, though this actual note had not been recorded previously and is thus new to the collecting pool. This note, from the middle of the run, was auctioned in Adams, Dublin on 12 April, 2015.

There were several interesting results among the banknotes in Whytes 'Eclectic Collector' auction of 14 May 2016.

Several rare banknotes were on offer, including a war code £20 note, dated 10.1.44, and a Ploughman Provincial Bank of Ireland £10 note with Kennedy signature, dated 17.7./39. Both notes were in decent grade, in the Fine region, and both were expected todo well. The results surpassed expectations.

The two notes were stiffly contested, with the Ploughman £10 note going to a room bidder, and the War code £20 going to a telephone bidder.

Prices were very strong for nicer grade material, with a good range of decent Ploughman notes on offer, with some notes being in numerical sequence. Lower grade notes fared less well, with weak prices for poorer items. However, almost all the banknote lots sold, with the handful of unsolds being confined to notes with serious problems.
This reflects the general trend in the banknote market.

There was a good attendance in the room for the sale, with many bids from phone bidders, and two web-based auction sites. Lots were knocked down to all of these.

Most of the estimates were far too high on the Ploughman £5 notes. Two thirds of them didn't sell. And there were too many similar notes—good for the collectors.

The Northern Bank Ploughman £10 note fetched a reasonable sum, $32,900 including fees (€29,200; £24,700), though at the lower end of the estimate range.
This is the highest price ever paid for a Ploughman note, and the second highest price ever paid for an Irish banknote.
Ploughman Ten Pounds Northern Bank sold for $32,900.

The Royal Bank of Ireland £5 note did well, at $2,350; ulster £10 at $5,287.

The Lavery £20 notes were appreciated, and fetched prices in line with what they would be expected to realise given their scarcity, at $822 (1946); $578, 1949).

The notes in this sale would probably have done better had they been sold by an auctioneer such as DNW in London, with more accurate descriptions and pre-sale estimates. The descriptions are rather puerile in some cases.

Whyte's Eclectic Collector auction on 21 January had a selection of rare issued Hibernian Bank Tokens on offer.

The best of the Hibernian Tokens, Lot 486 ,an intact cancelled £1 note in about VF grade, sold for 2,700 Euro plus fees (approximately 25% in total). A decent result for a rare item, and well above the pre-sale estimate.
Four more intact notes fetched between 660 and 1,800 Euro plus fees.
Cut cancelled notes in low grade fetched less than 200 euro each, which may be an undervaluation given the scarcity of these items. however, it is also relevant that these Hibernian Token issues are very much niche items in Irish note collecting.

The Whytes Eclectic Collector Auction on the 18th May had some interesting notes for sale.

A 1931 Ulster Bank £5 Ploughman with the Patton signature did particularly well. The estimate was 800-1000 but strong interest resulted in a hammer price of 2500 euro. This is a difficult note to get in nice grade and the results reflect this.

So this may be down to my limited 5 + years experience collecting Irish Banknotes, but I have been somewhat surprised at the prices realized on eBay for 10 shilling war notes. I realize eBay is perhaps not the best baseline for prices, but It seems a little erratic lately. For example a 7-9-40 sold yesterday for over $250 with writing on the back !! I was not aware, nor on checking on any publications that this was a rare date. Yet a similar year /code sells more recently for about $35 - any insights on this would be welcome

Auctions, and ebay in particular, can be very unpredictable in prices. It can depend on many things, such as whether interested buyers see it, or on how the listing is phrased, or if the picture looks good! Sometimes notes go cheap, other times they do very well indeed. A lot of the time on ebay they don’t sell as they are priced too high.

250 for a note with writing on the reverse would seem a bit high, though it depends on the grade of the note and on the degree of the writing.

Yes, the picture and grade are important factors when selling on ebay. Nice looking notes tend to do well but lower grade examples frequently sell for less than expected. Postage costs can also be a factor. Bidders are resistant to high postage costs for lower priced items. Bargains can be found on ebay, particularly over the summer months when collectors are away enjoying the summer sunshine !